22. If a diameter of a cylinder is increased by 20% and the height is decreased by 16 2/3 %, by what percent is the volume changed?
A. -10
B. 10
C. 20
D. 24
E. 83 1/2

Answer is C

I can do this problem but I would need more than a minute. What's the quickest way to do it?

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We are supposed to do the math out by hand? (possible, but that is just a waste of time and effort.) if only the 24% was not there, then the answer would have been much easier. (one could guess-timate the answer)